Note taking has evolved from using writing instruments on a surface, like pen and paper, to modern computing devices that receive and communicate numerous kinds of data electronically. Smart phones and tablet computers are powerful mobile computing devices that have enabled many new kinds of note taking and communications, but generally require direct interaction with a touch-screen or buttons on the device. Even the act of unlocking mobile computing devices requires direct physical interactions, such as entering a password or using a fingerprint scanner on the device. Such direct physical interactions can be inconvenient, particularly when the mobile computing device is not readily accessible (e.g., out of reach or stored in a bag or pocket).
Electronic writing instruments, like smart pens, do allow a user to write on a surface in a traditional manner, while recording the surface interactions on a connected computing device. However, such electronic writing instruments generally require a special writing surface and/or are not able to unlock the smart phone. It would be desirable to have a small accessory that could be used to unlock, activate, enter notations into, and even interact with the mobile computing device without the need for a special writing surface.